1. Technical Field
The present invention relates to creating an index for evaluating bronzing.
2. Background Technology
Sheet paper and other media as well as ink and other recording agents for accentuating the gloss of a printed object are known in the art. These recording agents and media are used in specific applications (for example, when there is a desire to heighten the image clarity of a photographic print or the like) and are a contributing factor to highlighting the texture of a printed object (e.g., see Patent Citations 1 to 3).
One known phenomenon occurring due to the aforesaid gloss is bronzing (also called the bronzing phenomenon). Bronzing is a phenomenon where, when a printed object is observed in a state of specular reflection relative to a light source, the coloring is perceived as being different from the observation in a normal state of diffuse reflection, simulating the appearance of a metallic gloss. The occurrence of bronzing in a printed object is not preferable, because the coloring of the printed object is altered by the relative positional relationship between the printed object and an observer. Bronzing is generated by various different factors, such as the combination of inks and other recording agents or the combination of the recording agent with the media onto which the recording agent is recorded.
For this reason, in a disclosed technique (e.g., see Patent Citation 4), the bronzing properties of a printed object are calculated on the basis of the hue thereof (strictly speaking, the L*a*b* value), and the calculated value is used in selecting an optimal combination of inks.
Japanese Laid-open Patent Publication No. 2005-194500 (Patent Document 1), Japanese Laid-open Patent Publication No. 2005-274340 (Patent Document 2), Japanese Laid-open Patent Publication No. 2010-52247 (Patent Document 3) and Japanese Laid-open Patent Publication No. 2007-288270 (Patent Document 4) are examples of the related art.